Parents will be able to share up to a year's leave to look after their newborn children under "radical" reforms set to be announced.
Deputy Prime Minister Nick Clegg said that from 2015 the UK will move to a new system of flexible parental leave as part of a huge shake-up of current arrangements. Under other changes, the right to request flexible working will be extended to all employees to encourage different work patterns for parents.
Mr Clegg is expected to say that "clapped out" rules and working arrangements need to be changed to give women a "real choice" after taking a break from work to have children.
The biggest change covers parental leave, so a mother will be able to trigger leave at any point so that whatever time is left to run on her original year off can be taken by her partner instead.
Parents will be able to "chop up" time together or take time off together, as long as no more than 12 months is taken in total, with no more than nine at guaranteed pay.
Mr Clegg said he had considered extending paternity leave from the current two weeks, but concern had been voiced within Government and from business groups about the cost. Flexible leave will be reviewed by 2018, when extending paternity leave will be looked at, Mr Clegg is expected to announce.
"These are major reforms and, at a time of continuing economic difficulty, it's sensible to do them in a number of steps, rather than one giant leap. More and more men are taking on childcare duties, or want to, and flexible leave builds on that."
Mr Clegg is also expected to say that a new legal right will be given to men to take unpaid leave to attend two antenatal appointments. Added to tax changes, Mr Clegg will say the reforms have the potential to transform opportunities for young parents considering starting a family.
He will say: "That means women up and down the country realising their potential, keeping their independence, fulfilling their dreams. It means children up and down the country benefiting from having their fathers in their lives. It means an economy running on all cylinders, and it means a nation reaping the rewards. Greater equality; a fairer society; a stronger economy too."
TUC general secretary Brendan Barber said: "The reforms will make it easier for parents to choose how they want to share their leave to look after newborn children... These reforms will make life easier for millions of working parents. Businesses will also benefit from a more engaged workforce and a larger pool of people to recruit from."
Tax tricks to improve your wealth
Shake-up of parental leave planned
If you wear a uniform of any kind to work and have to wash, repair or replace it yourself, you may be able to reclaim tax paid over the last four years. For some people, this could mean a windfall worth hundreds of pounds
The interest you receive on savings accounts (with the exception of cash Isas) is automatically taxed at a rate of 20%.
Higher-rate taxpayers therefore tend to owe money on the interest they are paid throughout the year. If, however, you are on a low income or not earning at all, you should be able to claim all or some of the tax deducted back
You can apply for a refund of vehicle tax if you are the current registered keeper or were the last registered keeper of your vehicle that no longer needs a tax disc
If you pay tax on a company, personal or State Pension through PAYE (the system employers use to deduct tax from your wages), you may well end up overpaying
There is a limit to the amount you need to pay in NI, whether or not you work for an employer.
Instances in which you may find that you have overpaid include if you work two or more jobs and earn more than £817 a week and if you move from self-employment to employment, but continue to pay Class 2 National Insurance contributions